This invention relates to a process for oxidation of olefinically-unsaturated compounds, and more specifically to a process for epoxidizing an olefinic compound in the presence of a soluble praseodymium catalyst.
The invention is useful in the synthesis of a broad range of epoxide compounds and specifically, for instance, in the conversion of allyl chloride to epichlorohydrin, and the preparation of dieldrin insecticide, and the preparation of a variety of aroma chemicals.
Numerous expidation processes are known in the prior art. Of particular interest is U.K. Patent Specification No. 963,430 which discloses a process for the epoxidation of an olefinic compound in which the double bond is in the terminal position and which contains at least 3 carbon atoms, by treatment of a liquid-phase mixture containing the olefinic compound and an aldehyde having at least two carbon atoms with oxygen, if desired in the presence of a solvent such as ethyl acetate and a catalyst which is preferably soluble in the reaction mixture, such as an organic cobalt or manganese salt.
Also of interest is U.S. Pat. No. 3,957,690 which discloses a process for the oxidation of propylene to propylene oxide, in the liquid phase, using a heterogeneous catalyst. The catalyst comprises a carrier with one or more oxides of scandium, yttrium, indium, gallium, thallium or rare-earth elements of the lanthanum group applied to its surface. Oxidation is effected using air, at high pressure, e.g., 50 atmospheres, and elevated temperature, e.g., 145.degree. to 170.degree. C. Conversion of propylene tends to be low, e.g., ranging from 13 to 32.5%.